In certain industries, it is necessary to handle powders that can be harmful and/or corrosive. Such handling often involves enabling a flow of such powder to be directed successively from one tube into a plurality of different tubes, for example for the purpose of packaging it. It is therefore necessary for a dispenser that is capable of directing the flow of powder appropriately to be disposed between the powder inlet tube and the powder outlet tubes.
Such a dispenser must often offer various advantageous properties. It must be sufficiently leaktight to avoid any leakage of powder, in particular in order to guarantee that the powder remains confined. It must also preferably be self-cleaning at the contact interfaces between its moving parts so as to avoid any premature wear on said surfaces due to the generally abrasive nature of the powder that is handled.
The dispenser of the present invention is a rotary powder dispenser between a top inlet pipe and at least two bottom outlet pipes, and it aims to satisfy all of these conditions.
Said dispenser is characterized in that it comprises:
a casing connected at its top to a powder inlet via which the flow of powder is taken in, and at its bottom to powder outlets via which said flow is delivered, said casing being formed of a bell-shaped shell whose bottom is fixed to a removable base;
a rotary plug that is disposed in said casing, that is of generally cylindrical shape, and that can turn about its own axis, the inside of said plug being provided with a duct which slopes relative to its axis and through which the powder flows under gravity, said plug being provided at its periphery with a ring of gear teeth that co-operate with a worm screw to rotate said plug, and with a cam that co-operates with at least one pusher external to said plug to determine the exact position of the plug; and
at least one and preferably two sealing system(s) disposed between a fixed surface of said casing and the moving surface of said plug to provide tightness between them.
Preferably, the rotary dispenser of the invention further comprises:
at least one wiper device acting, while said plug is rotating, to remove any powder that has built up in the empty spaces between the plug and the casing; and
at least one vibrator acting on the outside face of the casing to make it easier for the powder to flow.
The invention will be better understood on referring to the following description of an embodiment of the invention given by way of non-limiting example. In this description, certain secondary characteristics of the invention are specified.